Hypodermic syringe



Aug. 4, 1931.

A. E. SMITH 1,817,652

HYPODERMIC SYRINGE Ozu-iginal Filed May 18. 1925 leo Patented Aug. 4, 1931 UNITED."STATES P .LxfrErJ-roFritiriv f ARTHUR ERVINr SMITH, or Los ANGELES, oALrFoRivrA HYronEmVrIc SYRINGE Applcationled ,May18, 1925Se1'a1 No. 31,030. `Renewed SeptemberZS, i926. i

the several parts vbeing so correlated andar-- ranged that a freshly made medicinal preparationmay be quickly prepared and'jlnjected by the syringe without ever coming into contact with human hands, unsterilized receptacles' or with the atmosphere.

It is a further object ofthe invention to provide a syringe of the character indicated adapted to form the necessary fluid vtight joint between the ampu-les and-fthe syringe, with facility and dispatch and with very little trouble upon the partof the user.l

Further objects :of the "invention and Vrefinementsof construction-will be pointed out in the ,detailed description which follows:

' In the accompanyingfdrawings:

' Figure lvv is `an enlarged vertical sectional view of asyringe constructed inaccordance with the invention. ff

Figure 2 is a side elevation ofthe syringe upon'a smaller scale. v Figure 3 V's a magnified sectional View of the lower portion of the syringe, illustrating an elastic packing cone,and a discharge tube hereinafter described.

Figure 4 is a transverse sectional view upon line 4 4 of Figure 2. l

Figure 5 is a plan View ofthe structure illustrated in Figure 3,' upon a'smaller scale, and Figure 6 is a side View of the ampule, hereinafter described. i

Like y numerals designate lcorresponding parts in all of the figures of the drawings.'

The syringe of the present invention is particularly designed to discharge the contents of the ampule shown in Figure 6. This ampule-comprises a glass body 5, havinga tapered front end 6, which terminates in a breakable tip 7 This tip'is renderedfreadily separable fromV the remainder of the ampule by scoring, notching, etching, orv otherwise weakening it as lndicated at 8. The ampule contains a rubber or other stopper 9` -whichiis adapted toy actas a piston to expel the con.-

tents of the ampule through the open tapered end 6 of the ampule after it has beenbroken therefrom, as hereinafter described. IY preferably close the rear end of the ampule indi'- cated at 10 and wea-ken it byascored or'cut line,` at `1l., so that this rearlend may be readily broken therefrom.' Thus-'this closed rear end protects the stopper and maintains :the

whole in absolutely v sterile conditionuntil g thetime of use arrives. l Y 1 Certain medicinal compounds, and particularly certain anesthetics, are unstable-in 'soe lution and thisv disintegration uorfchemical change may produce deleterious effects upon the patient if 4such a "solution .was injected. Such medicinal compoundsshoul'd be freshly prepared at the timeof use... Infthe present case the l constituentv 'elements ofiltheI medicinalpreparation inthe ampules are main@ tained separate from` the vehicleuntil-the time of use arrives..1For examplethebody of liquid indicated at 12,in the ampule,may be distilled water, and an anesthetic i or .other medicinal preparationin th'eformof tablets or `powder may be contained within a'paraf- W5 fin or other waterproofcapsule 14, which is fusible or ,meltable underaxcomparatively low degree of heat.Thuswhenthetime of use arrives, by placing the ampule into warm water and increasing the. `temperature or i' holding 4it under running hot water,'the flow fusible wall may bemelted and the medicinal ingredients permitted to: -miXj with .the distilled water or other vehicle. .holdingthe ampule in a vertical position with itslarge end upward,- .the released parafn may be caused to travel upward `and find a seating in the concave face'9a of the stopperl 9, so that it Will thereafter constitute, in effect a part'of the piston in ej ecting the'medicin'al preparation through the open end ofthe am'- pule. When `the paraiiin rises itis still hot and in molten condition; kAfter it has entered and seated itselfin the `concave face ofthe stopper,l it is congealed and hardened, inconi tacttherewith, by; placing the ampule in cold water or holding it Iwith large end upward under, running cold water.. f

- fThesyringe comprises .af barrel 15,having a cross bar 16 for engagement by the fingers of the operator, the palm of whose hand engages a handle or cross bar 17 upon the upper end of a plunger rod 18. This plunger rod carries a plunger 19 at its inner end which is adapted to engage the stopper 9 and force said stopper downwardly to expel the liquid 12 from the ampule. The plunger rod 18 passes through a plurality of telescopic tubular members 20, 21 and 22 which may be multiplied in number to any desired extent. A spring 23 located Within these tubular members bears between a cap 24 and a head 25, of the innermost telescopic member 22. The cap 24 is adapted to be engaged with the upper end of the barrel 15 through a medium of a bayonet joint connection, of a usual and well known type, indicated at 25. The lower end of the barrel 15 is internally threaded to receive a cap 26, which terminates in a tapered tipadapted to receive a correspondingly tapered sleeve 28 of the hub 29 of a hypodermic needle 30. The cap 26 is internally formedwith a conical recess 31 which receives a correspondingly shaped rubber, or other compressible packing cone 432. The lower end of the barrel 15 is provided with a ring 33 having a beveled lower face 34 which is adapted to engage the upper and convex surface of the` cone 32 when the cap 26 is screwed into place, to thereby compress the cone 32 inwardly. The cone 32 is provided with a conical recess 35, which receives the tapered lower end of the ampule when the tip 7 is removed therefrom. The tapering shape ofthe lower end ofthe ampule causes it to have wedging engagement in the conical recess 35 and to tend to compress the material of the cone :outwardly- Thus this inward and outward compression of the cone results in establishing a fluid tight joint between the ampule and the cone upon the one hand and between the cone and the ring 33 upon the other hand. The disposition of the ring 33 is in such posi tion that its contact with the cone 32 in the manner illustrated insures that the ampule will not be forced downwardly far enough for it to be ruptured by contact with the ring 33. AA discharge tube 37 is soldered into engagement with the tip and its Alower end opens into the needle 30. However, its upper end is preferably closedas indicated at 38 lin Figure 3. It will be noted that the discharge tube projects upwardly into conical recess 35 so that .its upper portion lies free of contact with the cone 32. Ths permits the liquid of the ampule to find access to the interior `of the discharge tube 37 by passing through lateral openings 39 formed in the discharge tube adjacent the upper ends thereof. The reason for arranging the parts in this relation is to prevent any possibilty that the paraiiin or other low fusible material released when the ampule is heated, will close the discharge tube Aupon the linal inward movement of the plunger. Y

In use the ampule is charged into barrel 15, after the plunger and associated parts have been removed by the release of the bayonet connection between the cap 24 and barrel 15, and after the rear portion 10 of the ampule has been removed by breaking it olf along the line 11, and after breaking the ampule tip 7 at 8. Then when the plunger is restored and the bayonet connections are engaged, the head 25 bears with yielding tension upon the rear edge 40 of the ampule and forces the tapered lower end of the ampule into the conical recess 35 of the cone 32.

Then when the plunger rod and plunger 18 are thrust downwardly, the plunger 19 engages the stopper 9 and forces said stopper into the ampule after the manner of a piston. This pressure upon the liquid in turn tends to force the ampule downwardly and increases the pressure upon the packing cone and associated parts, expelling the liquid from the interior of the ampule through the openings 39, discharge tube 37 and needle 30 in a manner, which will be readily under-` stood. l

Since the head 25 is rendered yielding by reason of its telescopic mounting and the presence of the spring 23 it follows that it may be positioned at varying points in the length of the barre-l and still exercise its function. By virtue of this arrangement, the one syringe is adapted to handle ampules of varying lengths and consequently of varying cubic capacities. Thus ampules ranging from one cubic centimeter to fourl cubic centimeters, or any fraction thereof, may be eiliciently handled in the one syringe. This is not possible with vany device of this charac-ter of which I have knowledge.. y

While I prefer to use the discharge tube with the openings laterally disposed below the vupper end thereof and with the upper end closed, thisis not essential in the case of ampules whichV do not utilize paraffin or the like. Thus it is to be understood that the invention includes the use of Va discharge tube having an open top.

I preferably leave the sides of the lbarrel 15 open as indicated at 15a to constitute a sight opening through which the contents of the ampule will be visible and so thatV the movement of the cork 9 and the extent to which the contents of the ampule have been discharged, may be readily observed by the surgeon or dentist.

Furthermore this renders it possible for the operator to see the `conical opening 35 in the upper end of the cone 32 and -aids in positioning the broken 0E lower end of the ampule. n f. Y

l/Vhen the piston constituted V'by the stopper and the paraliin, starts tomove downwardly, the pressure forces the paraffin into the con- `cave face of the cork and causes lateral :expansion of the relatively thin edges yof the cork against the wall of the ampule, thus making an absolutely nonleakable joint between the piston and the ampule At the same time the pressure applied in the expulsion of the medicinal solution, tends to force the ampule toward the rubber cone and this in turn forces the small end of the ampule into the cone shaped depression of the rubber cone, making a nonleakable joint between the outer part of the glass tip and the said cone. Furthermore, 'the pressure forces the rubber cone itself into its tapered socket, thereby compressing the rubber cone against the needle or tube, thus making a nonleakable joint between the tube and the rubber cone.

It is to be understood that the invention is not limited to the precise construction set forth but that it includes within its purview whatever changes fairly come within either the terms or the spirit of the appended claim.

Having described my invention, what I claim is:

A syringe of the character described comprising a barrel, having a sight opening formed therein, a cap adapted to be screwed into the lower end thereof, said cap having a tapering recess formed therein, a conical. rubber packing element seated in said recess, a discharge tube extending through said packing element and permanently united with the cap and having a closed upper end with lateral openings therebelow, said packing element having a conical recess formed in its upper face adapted to receive the broken off nose of an ampule, a plunger rod, a spring surrounding said plunger rod, a handle for operating the plunger rod, a removable cap on the barrel, a plurality of telescopic elements surrounding the plunger rod, said spring bearing between said cap and the lowermost of said telescopic element-s and a head carried by the lowermost telescopic elements adapted to engage the rear end of an ampule to force its nose into engagement with the tapered recess of the rubber packing element.

In testimony whereof I hereunto aiix my` signature.

ARTHUR ERVIN SMITH. 

